L. Fiscarelli, O. Dunkel, S. Russenschuck, S. Izquierdo Bermudez, G. Willering, J. Feuvrier 21 st July 2015

Click here to add footer 2 Outline MM systems (ambient and cryogenic temperature) Performed measurement cycles Results Straight section TF Allowed multipoles Other multipoles Comparison with ROXIE model Comparison with MBHSP101 Ramp-rate dependency Integral field Cold/Warm correlation Conclusions

Click here to add footer 3 Measurement system 300 K  Motor + encoder + slip-ring unit (MRU)  Fast Digital Integrator (FDI)  FuG low voltage power supply (40 V, 20 A)  DCCT Hitec MACC-plus  Search coil shafts (radius 22 mm, length 1.2 m)  Flexible software Framework for Magnetic Measurements (FFMM) A measurement is the average over 1.2 m Number of turns(-)256 Inner width(mm)13.41 Inner length(mm) Groove thickness(mm)1.4 Magnetic surface(m2)3.37 Center radius(mm)21.33

Click here to add footer 4 Measurement system 1.9 K  Flexible software Framework for Magnetic Measurements (FFMM)  Fast Digital Integrators (FDI)  Motor + encoder + slip-ring unit (MRU)  Vertical rotating shaft in liquid He A measurement is the average over 250 mm Number of turns-36 Inner widthmm10.3 Inner lengthmm Groove thicknessmm0.57 Magnetic surfacem2m Center radiusmm

Click here to add footer 5 Performed measurement cycles At 1.9 K Stair-step cycle 3x machine simulation cycles Ramp-rate study at 20, 50, and 100 A s -1 Long flat-top (10 h) before a machine cycle No measurements at 4.3 K Standard program

Click here to add footer 6 Transfer function o Measurements and ROXIE model in agreement for geometric TF o Saturation overestimated by the model (+55 units) o Measurement results on MBHSP101 and MBHSP102 are consistent

Click here to add footer 7 Transfer function Possible sources of error: Iron properties Using data from LHC production the discrepancy decrease by 20 units (from ~70 to ~50 units) Packing factor of the yoke laminations Its effect is up to ~15 units Geometric Rather big displacements needed to explain 50 units (350 µm smaller coil gives ~15 units) Courtesy of S. Izquierdo Bermudez

Click here to add footer 8 The main source of error is the magnetic properties of the iron: Discrepancy ~ 80 units using ROXIE bhdata2 Discrepancy ~ 55 units using LHC production data Discrepancy ~ 15 units using a modified bh data based on [1] Modification on the BH data based on Wlodarski empirical relation. Nom. Correspond to the parameters reported in S. Russenschuck book [1] Z. Wlodarki. Analytical description of magnetization curves Critical region! Transfer function Courtesy of S. Izquierdo Bermudez

Click here to add footer 9 Allowed multipoles Reference radius 17 mm  b3 changes by ~22 units during ramp  Offset on allowed multipoles after long plateau at nominal

Click here to add footer 10 Allowed multipoles Reference radius 17 mm  Slow decay of b3 during long plateau at nominal ~0.5 units  Decay at injection ~1.2 units

Click here to add footer 11 Comparison with ROXIE (2D) Reference radius 17 mm  Offset of +5 units on b3  Offset on other allowed multipoles  Discrepancy on persistent currents

Click here to add footer 12 Comparison with MBHSP101 Reference radius 17 mm  Offset added on data from MBHSP102  Larger persistent currents on MBHSP102

Click here to add footer 13 Ramp-rate dependence Reference radius 17 mm 20 A s A s A s A s A s A s -1 n Δ Bn Δ An mT

Click here to add footer 14 Other multipoles Reference radius 17 mm 300 K at 20 A 1.9 K at 5 kA on three segments 1.2 m seg3seg4seg5 σ nbnan bnanbnanbnan bnan

Click here to add footer 15 Integral field Reference radius 17 mm 300 K 1.9 K nbnan bnan units at 17 mm  Multipoles in agreement with respect to measurements at 300 K.  Thermal contraction of measurement shaft to be checked

Click here to add footer 16 Cold/Warm correlation Reference radius 17 mm

Click here to add footer 17 Conclusions MBHSP102 has been tested at room temperature cryogenic temperature Comparison with model TF in agreement for geometric Model overestimates saturation Offset on allowed multipoles Cold/Warm in general agreement